How Much Sourdough Starter Should You Use? 8 Practical Tips

When you start perfecting your sourdough bread recipe, one big question often comes up: how much sourdough starter should you use? This decision depends on several factors, including the weather, humidity, and the type of flour you choose.

Your sourdough starter is a mix of wild yeast and friendly bacteria that makes your dough rise and gives your bread that tangy flavor. By playing with the amount of starter, you can change the sourdough flavor profile of your bread.

Interesting? Let's discover how to determine the right starter amount to make your bread more or less sour, or just right.

How much sourdough starter should you use?

To keep things simple as a beginner, start with this general rule: use 20% sourdough starter (by weight) compared to the amount of flour in your recipe.

For example, if your recipe calls for 500 grams of flour, use 100 grams of starter. This is the same ratio I use in my Beginner's Sourdough Bread recipe and Master Sourdough Bread recipe.

If you'd like to understand the exact math behind these numbers, I explain inoculation percentage in sourdough baking in another blog post.

How to adjust the amount of starter

You can change the amount of starter depending on several factors:

1. Temperature

Warm weather makes your starter more active and shortens fermentation time. In this case, you can decrease the starter to 5-10%.

Cold weather slows fermentation, so you may need to increase the starter to 25-30%.

For overnight bulk fermentation, use less starter: 5-10% in summer and 15-20% in winter. For daytime fermentation, increase it to 20-25%.

2. Humidity

In humid conditions, you also need to adjust the amount of starter in your recipe. Higher humidity leads to faster fermentation, so consider using less starter.

In drier conditions, you need to increase the amount of starter to kick-start the fermentation.

3. Altitude 

At higher altitudes, lower air pressure speeds up yeast activity and fermentation. To prevent overproofing, reduce the amount of starter.

At lower altitudes, fermentation is slower, so you may need to use slightly more starter for proper leavening.

4. Type of flour

Another factor that affects the ratio is the type of flour used. Different flours absorb water differently and affect the starter's overall hydration level, which in turn affects bulk fermentation.

• High-protein flour (like bread flour) absorbs more water and creates a stiffer starter. In this case, you may need to use more starter in the recipe to achieve proper fermentation and a rise in the dough.

• Low-protein flour (like all-purpose flour) is softer and may need less starter to balance the dough hydration.

Sourdough hydration is still mainly adjusted with water, but flour choice plays a supporting role.

5. Sourdough starter hydration

A liquid starter (high hydration) contains more water and ferments faster. You typically need less of it to avoid over-fermentation.

A stiff starter (low hydration) contains less water and usually requires more starter in the recipe for proper leavening.

A 100% hydration starter is the most common and beginner-friendly option, though this can vary depending on baking style and bread type.

6. Bulk fermentation

You can adjust the amount of starter depending on the available time for bulk fermentation.

If you are short on time and need faster fermentation, use more starter to speed things up. This approach works well for the Same-Day Sourdough Bread recipe, such as that using 30% starter.

If you have more time and want slower fermentation with deeper flavor, use less starter. This results in a longer bulk fermentation and a more complex taste.

7. Sourdough flavor

Finally, the amount of starter depends on the desired flavor.

To make your sourdough more sour, increase the starter to 25-30% of the flour weight. This speeds up fermentation and produces a stronger, tangier taste.

If you prefer your sourdough less sour, reduce the starter to 4-10%. This slows down bulk fermentation, resulting in a milder, less tangy loaf.

8. Batch baking

When baking multiple sourdough loaves, you can use less starter (10-15%) to slow down the fermentation. This approach provides additional "catch-up" shaping time without overproofing the dough.

However, the total amount of starter will depend on the total flour weight in the batch. This is where a sourdough baking calculator becomes very helpful.

When baking a larger batch of bread, scale the sourdough starter proportionally so that all the loaves ferment evenly and rise properly.

FAQ

Can you use too much sourdough starter?
Yes. Using too much starter can cause the dough to ferment too quickly, leading to overproofing and an overly sour flavor.

What happens if you use too little sourdough starter?
Too little starter slows fermentation and may result in dense bread with poor rise, especially in cold kitchens.

Can I change the amount of starter without changing the recipe?
Yes, but you will need to adjust dough hydration and bulk fermentation, especially if you make big changes to the starter amount.

Is 20% starter a good amount for beginners?
Yes. As a beginner, use 20% starter based on flour weight.

Let's talk sourdough

Have you ever experimented with the amount of starter you used in your sourdough bread? Did it change the flavor, texture, or maybe your baking schedule? Please share your experience in the comments.

Ready to keep learning?

After dialing in quantity, learn when to use sourdough starter after feeding, at peak, before peak, or after peak, and how each stage changes your dough.